Both. The one doesn't exclude the other. I'm a heavy user of text-to-speech at high rates to digest content easily, but prefer braille when coding or doing some work on a shell/terminal.

You'll see much more braille displays in some European countries because they get subsidized by health insurance or a government entity that provides assistive technology for the workplace. This workstation has a 88 cell braille display, which means it can display 88 braille characters at a time. That unit costs $10k or so, depending on market and EUR/USD rate etc, but to give you an idea of the price tag. I also have a mobile unit with 40 cells, I guess that one is about $6k or so.